So after about a month my Mt6000 started acting up, losing internet. somewhere ping was around 50-100msor none at all. i have a backup mt3000 so after switching back and forth between devices and ports ive found that the WAN port on mt6000 has become faulty? switching same cable to WAN/LAN1 has resolved the issue. but i need 2.5g on both wan and lan so maybe any ideas why my primary WAN port is acting up?
What firmware do you have installed on the router? Try to reset your router and try to reproduce the issue.